In order to meet the increasing wireless data traffic demand since the commercialization of 4th generation (4G) communication systems, the development focus is on the 5th generation (5G) or pre-5G communication system. For this reason, the 5G or pre-5G communication system is called beyond 4G network communication system or post long term evolution (LTE) system.
In order to accomplish high data rates, consideration is being given to implementing the 5G communication system on the millimeter Wave (mm Wave) band (e.g., 60 GHz band). In order to mitigate propagation loss and increase propagation distance, the 5G communication system is likely to accommodate various techniques such as beamforming, massive multiple input multiple output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and large scale antenna.
Also, for throughput enhancement of the 5G communication system, research is being conducted on various techniques such as small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network, device to device (D2D) Communication, wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), and interference cancellation.
Furthermore, the ongoing research includes the use of hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) modulation and sliding window superposition coding (SWSC) as advanced coding modulation (ACM), filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA). Meanwhile, there is a need of a method for configuring a contention window (CW) for channel sensing to use an unlicensed band.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.